Everyone enjoys a good explosion or long distance launch.  Learn to build your own canon project uses a simple ingredient – dry ice (frozen carbon dioxide) which goes directly from solid to gas. The process called sublimation releases a lot of the built up pressure.  Consider this…1 pound of dry ice turns to gas and gives you 250 liters of gas! That’s a lot of gas and a lot of latent propellant. The water fast tracks the form change of the dry ice creating an explosive propellant.

It’s essential to pay attention to the build of the canon itself with all that charged up gas. Over pressurization is a hazard. Note the careful mechanism of the canon in the video. The canon is entirely made up of steel and tightly welded together. A PET bottle is connected to the explosion chamber using a CNC adapter. Dry ice is poured into the PET bottle and water is injected through another bottle to trigger the process. The escaping gas launches a front loaded projectile through the barrel.

The added exhaust valve acts as a pressure release valve and is the first safety feature. The second one is a pressure gauge which monitors the critical pressure when the PET bottle explodes.  The range according to the makers is around 80 meters. The cost? $200.  The shoulder fired bazooka uses a simple chemistry principle. Fun, but serious so always use safety precautions.

Here’s more ammunition for your thoughts in our gallery of Airsoft and Gun projects.

• Head Mounted Water Canon = Summer Fun
• Incredible Gas Powered Vortex Canon
• Pirate Cannon – Pneumatic Style

Have a spare car lying in the driveway? Convert it to run on trash. Jim Mason did this by using his “gasifier” to transform solid dry organic trash such as wood chips or nut shells into a synthetic fuel. Whether you have an Accord or not, his project is a fantastic learning tool.  The project is separated into several parts:

• How to assemble it
• How to build the “gasifier”
• How to use it

Be sure to browse our other DIY Free Energy and DIY Car projects:

• How to: Harness Solar and Wind Energy
• How to Go Green this Winter with DIY Free Heating
• 3 Ways to Install a Game Console in your Car